Wave transmission lines and networks – Coupling networks – Wave filters including long line elements
Reexamination Certificate
2002-10-28
2004-09-14
Summons, Barbara (Department: 2817)
Wave transmission lines and networks
Coupling networks
Wave filters including long line elements
C333S212000, C333S250000
Reexamination Certificate
active
06791438
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a radio frequency module on which a radio frequency semiconductor integrated circuit is to be mounted for use in radio communications, and to a method for manufacturing such a radio frequency module.
BACKGROUND OF THE INVENTION
There is conventionally known a radio frequency module forming a waveguide in a multi-layer substrate, as described in 1999 IEEE MTT-S Microwave International Symposium Digest, pp. 453-456. In this structure, conductors are provided on the both surfaces of a multi-layered dielectric substrate. An air gap, constituting a waveguide, is formed in the dielectric substrate to provide through-holes in wall regions of the air gap. Meanwhile, conductors are provided between the layers of the dielectric substrate, to form waveguide walls in a lattice form using the through-holes and conductors. The air gap in the dielectric substrate serves as a waveguide defined by the upper and lower conductors and the lattice-formed walls, allowing a radio frequency to propagate.
In this radio frequency module, the waveguide on-wall conductor is formed in a lattice by the through-holes and the conductors. In a basic propagation mode TE10 of the waveguide, a current flows parallel with a traveling direction of a radio wave relative to the waveguide wall, raising a problem that conductor loss is increased by a discontinuity resulting from a lattice-formed structure of the wall conductor. With respect to this problem, such loss can be reduced by providing through-holes sufficiently short relative to the wavelength or by increasing the number of layers in the multi-layer substrate. In a millimeter-wave band, however, the wavelength in a free space ranges from 10 millimeters to 1 millimeter. Consequently, the discontinuity on the wall surface is not negligible relative to the wavelength, and hence loss inevitably increases. In particular, because the wavelength in a dielectric substrate is inversely proportional to a square root of an effective relative dielectric constant, the effect increases furthermore.
Meanwhile, the conventional rectangular waveguide is manufactured by metalworking. This, however, incurs a problem to increase material cost and time required in working.
SUMMARY OF THE INVENTION
The present invention is to solve the foregoing problem, and it is an object to provide a radio frequency module having a waveguide circuit which is reduced in loss of a radio frequency current flowing through a wall surface thereof, excellent in connectability to other circuits and low in cost but high in performance.
It is another object of the present invention to provide a manufacturing method thereof.
A radio frequency module of the present invention comprises: a dielectric substrate having first and second main surfaces and a rectangular penetration hole opening in the first and second main surfaces; first and second conductors for grounding respectively provided on the first and second main surfaces to cover the openings of the penetration hole; and a conductor layer formed on opposite inner wall surfaces in the penetration hole of the dielectric substrate; whereby a waveguide structure is configured by the first and second conductors and the conductor layers.
According to the radio frequency module, by structuring a wall surface of the waveguide using dielectric with a continuous conductor material surrounding the same, it is possible to reduce the loss of a radio frequency current flowing through the wall surface. The dielectric substrate itself, in a planar structure, is excellent in connectability to other circuits. In forming a wall-surface conductor, there is no need to form through-holes or making a substrate with layers. It is accordingly possible to realize a radio frequency module having a waveguide circuit that is low in cost but high in performance.
Meanwhile, the method for manufacturing a radio frequency module comprising the steps of: forming, by laser forming, a penetration hole having a plurality of rectangular portions coupled one with another in a first dielectric substrate formed, on a first main surface, with a conductor to reach the conductor; forming a metal film on an inner wall surface of the penetration hole; and joining a second dielectric substrate forming a conductor on one surface and an input/output line on the other surface, at the conductor surface, onto the other surface of the first dielectric substrate forming the metal film through a conductive double-sided adhesive sheet worked with a blank hole in a form of the penetration hole.
According to the manufacturing method, it is possible to realize, in a waveguide structure formed in a dielectric substrate, a continuous wall-surface structure for reducing conductor loss by a general working process at low cost and on a mass-production basis.
REFERENCES:
patent: 3292115 (1966-12-01), La Rosa
patent: 3613034 (1971-10-01), Linnd et al.
patent: 3680012 (1972-07-01), Moreau
patent: 4216448 (1980-08-01), Kasuga et al.
patent: 4677402 (1987-06-01), Cesani et al.
patent: 5739733 (1998-04-01), Cameron
patent: 5821836 (1998-10-01), Katehi et al.
patent: 6191670 (2001-02-01), Nguyen
patent: 6523248 (2003-02-01), Snygg et al.
patent: 3-77402 (1991-04-01), None
H. Uchimura et al. “A Ceramic Planar 77GHz Antenna Array”, 1999 IEEE MTT-S International Microwave Symposium Digest, pp. 453-456, Jun. 13-19, 1999.
Fujita Suguru
Ogura Hiroshi
Takahashi Kazuaki
Matsushita Electric - Industrial Co., Ltd.
RatnerPrestia
Summons Barbara
LandOfFree
Radio frequency module and method for manufacturing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radio frequency module and method for manufacturing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radio frequency module and method for manufacturing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3211003